4Remark  The RSI is known to generalize several extensions of convexity, such as quasar-star convexity [1]} and strong star-convexity [2]}. Refer to [3]} for a comparison with other constraints such as the Polyak-Lojasiewicz (PL) inequality, and the quadratic growth condition which we study in sec:quadratic. In general, the RSI is a significantly weaker condition than global strong convexity.

